From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 10 Aug 2001 12:38:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 10 Aug 2001 12:37:58 -0400 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:19818 "EHLO flinx.biederman.org") by vger.kernel.org with ESMTP id ; Fri, 10 Aug 2001 12:37:48 -0400 To: Johannes Erdfelt Cc: Mike Jadon , linux-kernel@vger.kernel.org Subject: Re: PCI NVRAM Memory Card In-Reply-To: <5.1.0.14.0.20010622101907.03ac21b0@192.168.0.5> <20010810114011.X3126@sventech.com> From: ebiederm@xmission.com (Eric W. Biederman) Date: 10 Aug 2001 10:31:08 -0600 In-Reply-To: <20010810114011.X3126@sventech.com> Message-ID: User-Agent: Gnus/5.0808 (Gnus v5.8.8) Emacs/20.5 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Johannes Erdfelt writes: > On Fri, Aug 10, 2001, Eric W. Biederman wrote: > > Mike Jadon writes: > > > > > My company has released a PCI NVRAM memory card but we haven't developed a > Linux > > > > > > > driver for it yet. We want the driver to be open to developers to build > upon. > > > > Is there a specific path we should follow with this being our goal? > > > > You might want to check out the development of the mtd subsystem. > > http://www.linux-mtd.infradead.org/ > > > > This is probably what you want to write a driver for for your NVRAM PCI card. > > Not really. > > In their case, it's a bunch of standard SDRAM on a PCI card with a > battery backup. It's not flash. > > A block device is all that's needed. O.k. that make sense, NVRAM has so many meanings... It still might make sense to support things like JFFS, and friends, though. So the reference isn't totally wasted. Somehow I missed the reference to a description of what kind of hardware is being discussed. I wonder if the card can do DMA. Without bus mastering it looks tricky to get burts over the PCI bus, which would intern mean the card would be relatively slow. And for things like keeping a journal for your filesystem generally the faster the better. Being able to get 128MB/s would be pretty cool. Eric